Following up on this, there are currently 4 units on Ebay going way below Hyatt prices. Is it really that bad or difficult to use?
The post to which you are "following up" is nearly 10 years old now. Aside from that significant time gap, I am confused by your reference to "Hyatt prices" in a discussion thread about Coconut Mallory, which has no affiliation of any kind with Hyatt (and never did).
In any event, Coconut Mallory is just barely on Key West, being just over the entry point from Stock Island. In other words, you could not possibly be
any further away from the Mallory Square area at the opposite end of Key West if / when staying at Coconut Mallory.
Location aside, when we owned at Coconut Mallory we found there to almost
always be unresolved maintenance / repair issues and problems, coupled with a staff that that was consistently disinterested, bordering on hostile. We were very happy to unload that CM ownership after a few years of use and disappointment. We had acquired it (resale) for peanuts and gladly re-sold it for even less. We now just rent (usually at Hyatt Sunset Harbor, directly from HSH owners) once every few years if / when we want to go to Key West.
We hope to be able to rent a winter week at The Banyan sometime --- but that "sometime" will be in future, better, non-COVID times.
Fwiw, I also think that the "all floating weeks" model at CM is unappealing to many people, requiring timely (and time consuming) participation in the "phone reservation lottery" (their window opens each September, iirc) to book a week that you actually want. We had decent luck with that reservation process, but too many other shortcomings at CM were ultimately show-stoppers for us. YMMV.